Many previous generations of disk drives employed a status indicator of some type which provided the disk drive user with messages about the operating condition of the disk drive. Frequently, the status indicator was visual in nature, and comprised one or more LEDs connected to indicate the disk drive operating state (e.g., idle, seek, read or write) or the disk drive condition (e.g., improper spindle speed, bad disk lock, open door).
Although more recent generations of fixed disk drives often eliminate these status indicators, removable disk drive systems continue to provide their users with status information independent of the host system. The removable nature of the cartridges in such systems makes user feedback valuable and important.
As disk drives are manufactured in smaller and smaller form factors, the space available for visual indicators has steadily decreased. The trend in the disk drive industry has also been toward lower overall component counts and lower product cost. Very small form factors, e.g., 1.8 inch PCMCIA cartridge drives, are frequently placed inside a host enclosure and any conventional visual status indicator may not be readily seen by the user. As a result, there is an increasing need to develop alternative indicator technologies which can replace conventional visual status indicators.